Numerous bioactive materials are available commercially. They are conventionally incorporated in a variety of vehicles and are used as preservatives in personal care products, in drugs, in household and industrial products such as paints, fuels, and the like, and in other compositions wherein their effect is sought. Other bioactive materials are used for disinfecting surfaces. These include room disinfectants, detergent compositions, and the like. Still other such materials find important agricultural purposes such as pesticides.
The use of polymers for bioactive applications is not broadly new. With respect to the present invention, reference is made to applicant's U.S. Pat. No. 3,016,327, issued Jan. 9, 1962, which is incorporated herein by reference. See also U.S. Pat. No. 2,428,329 (Ham, Sep. 30, 1947) (cited in U.S. Pat. No. 3,016,327); U.S. Pat. No. 3,102,108, (Ed. Geistlich Soehne AG, Aug. 27, 1963); J. R. Woodward and M. S. Korczynski, "Applications of a Halogen-Resin Complex in Water Purification", Chapter 45 in Developments in Industrial Microbiology, Volume 14. Washington, D.C.: American Institute of Biological Sciences, 1973; U.S. Pat. No. 3,428,607 (Renner, Feb. 19, 1969); U.S. Pat. No. 4,071,670 (Vanzo and Lewis, Jan. 31, 1978); U.S. Pat. No. 3,928,272 (Brancato and Herman, Dec. 23, 1975); and German Patent Application DE 2831192 (Pfaudler-Werke AG, Jan. 1, 1980).
U.S. Pat. No. 3,102,108 describes bacteriostatic polymers, especially urea-formaldehyde condensates. They are said to take the form of substantially linear chains, possibly lightly cross-linked. The patent indicates that many of the nitrogens of urea formaldehyde condensates form hydroxymethylene groups and that the presence of those groups is reflected in the properties of the products.
The bacteriostatic products of U.S. Pat. No. 3,102,108 are prepared by condensing urea and formaldehyde under alkaline conditions and then spraying the condensate through a rotary nozzle into a drying tower at elevated temperatures to form a condensation product in the form of a white powder. That powder is used as a dusting powder in ointments, suspensions, or in tablets.
Schmitz et al., U.S. Pat. No. 3,016,327, describes germicidal compositions comprising solid or liquid soap or nonionic detergent containing active biocidal agent, the latter being colloidal particles of an alkali-activated or basic anion-exchange resin which is preferably a urea-guanidine-formaldehyde condensate. In the patent, the colloidally sized particles of polymer are prepared by procedures known in the art such as, for example, the methods of U.S. Pat. Nos. 2,251,234 and 2,285,750 and in U.S. Pat. No. 2,434,190. These methods relate to the preparation of water insoluble, anion-active resins, the molecular weight of which is a function of the degree of condensation and cross linking. It is said to be critical to reduce the resin prepared in the condensation reaction to a colloidal size in order to effectively disperse the material in a vehicle and to insure that the desired germicidal phenomena take place.
In the patent, polymer syrup formed under alkaline conditions is acidified under constant agitation to a pH of 4. The acidified product is slowly cooled, during which time transition into the gel state is initiated due to the acidification, and proceeds to completion. At room temperature, the acidified gel continuum is broken up into granules of approximately 8 mesh. The granules are oven-dried first at about 55.degree. C. for 6 hours, and finally at 100.degree. C. for 1 hour. The dried, hardened, mechanically rigid anion-exchange resins are ground and treated with an alkaline solution. The pH adjusted "alkali activated" anion-active resin granules are then washed, separated by filtration, and oven-dried, before being micropulverized. Finally, the micropulverized resin particles are passed through a micro-atomizer. The resultant product may then be incorporated into any number of vehicles for its ultimate use.